﻿// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Collections;
using System.ComponentModel;
using System.ComponentModel.Design.Serialization;
using System.Globalization;
using System.Reflection;

namespace System.Windows.Forms
{
    /// <summary>
    ///  SelectionRangeConverter is a class that can be used to convert
    ///  SelectionRange objects from one data type to another.  Access this
    ///  class through the TypeDescriptor.
    /// </summary>
    public class SelectionRangeConverter : TypeConverter
    {
        /// <summary>
        ///  Determines if this converter can convert an object in the given source
        ///  type to the native type of the converter.
        /// </summary>
        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
        {
            if (sourceType == typeof(string) || sourceType == typeof(DateTime))
            {
                return true;
            }
            return base.CanConvertFrom(context, sourceType);
        }

        /// <summary>
        ///  Gets a value indicating whether this converter can
        ///  convert an object to the given destination type using the context.
        /// </summary>
        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
        {
            if (destinationType == typeof(InstanceDescriptor) || destinationType == typeof(DateTime))
            {
                return true;
            }
            return base.CanConvertTo(context, destinationType);
        }

        /// <summary>
        ///  Converts the given object to the converter's native type.
        /// </summary>
        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
        {
            if (value is string)
            {
                string text = ((string)value).Trim();
                if (text.Length == 0)
                {
                    return new SelectionRange(DateTime.Now.Date, DateTime.Now.Date);
                }

                // Separate the string into the two dates, and parse each one
                //
                if (culture == null)
                {
                    culture = CultureInfo.CurrentCulture;
                }
                char separator = culture.TextInfo.ListSeparator[0];
                string[] tokens = text.Split(new char[] { separator });

                if (tokens.Length == 2)
                {
                    TypeConverter dateTimeConverter = TypeDescriptor.GetConverter(typeof(DateTime));
                    DateTime start = (DateTime)dateTimeConverter.ConvertFromString(context, culture, tokens[0]);
                    DateTime end = (DateTime)dateTimeConverter.ConvertFromString(context, culture, tokens[1]);
                    return new SelectionRange(start, end);
                }
                else
                {
                    throw new ArgumentException(string.Format("Text Parse Failed Format:{0},{1}",
                                                              text,
                                                              "Start" + separator + " End"));
                }
            }
            else if (value is DateTime dt)
            {
                return new SelectionRange(dt, dt);
            }

            return base.ConvertFrom(context, culture, value);
        }

        /// <summary>
        ///  Converts the given object to another type.  The most common types to convert
        ///  are to and from a string object.  The default implementation will make a call
        ///  to ToString on the object if the object is valid and if the destination
        ///  type is string.  If this cannot convert to the desitnation type, this will
        ///  throw a NotSupportedException.
        /// </summary>
        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
        {
            if (destinationType == null)
            {
                throw new ArgumentNullException(nameof(destinationType));
            }

            if (value is SelectionRange range)
            {
                if (destinationType == typeof(string))
                {
                    if (culture == null)
                    {
                        culture = CultureInfo.CurrentCulture;
                    }
                    string sep = culture.TextInfo.ListSeparator + " ";
                    PropertyDescriptorCollection props = GetProperties(value);
                    string[] args = new string[props.Count];

                    for (int i = 0; i < props.Count; i++)
                    {
                        object propValue = props[i].GetValue(value);
                        args[i] = TypeDescriptor.GetConverter(propValue).ConvertToString(context, culture, propValue);
                    }

                    return string.Join(sep, args);
                }
                if (destinationType == typeof(DateTime))
                {
                    return range.Start;
                }
                if (destinationType == typeof(InstanceDescriptor))
                {
                    ConstructorInfo ctor = typeof(SelectionRange).GetConstructor(new Type[] {
                        typeof(DateTime), typeof(DateTime)});
                    if (ctor != null)
                    {
                        return new InstanceDescriptor(ctor, new object[] { range.Start, range.End });
                    }
                }
            }
            return base.ConvertTo(context, culture, value, destinationType);
        }

        /// <summary>
        ///  Creates an instance of this type given a set of property values
        ///  for the object.  This is useful for objects that are immutable, but still
        ///  want to provide changable properties.
        /// </summary>
        public override object CreateInstance(ITypeDescriptorContext context, IDictionary propertyValues)
        {
            try
            {
                return new SelectionRange((DateTime)propertyValues["Start"],
                                          (DateTime)propertyValues["End"]);
            }
            catch (InvalidCastException invalidCast)
            {
                throw new ArgumentException("Property Value Invalid Entry", invalidCast);
            }
            catch (NullReferenceException nullRef)
            {
                throw new ArgumentException("Property Value Invalid Entry", nullRef);
            }
        }

        /// <summary>
        ///  Determines if changing a value on this object should require a call to
        ///  CreateInstance to create a new value.
        /// </summary>
        public override bool GetCreateInstanceSupported(ITypeDescriptorContext context)
        {
            return true;
        }

        /// <summary>
        ///  Retrieves the set of properties for this type.  By default, a type has
        ///  does not return any properties.  An easy implementation of this method
        ///  can just call TypeDescriptor.GetProperties for the correct data type.
        /// </summary>
        public override PropertyDescriptorCollection GetProperties(ITypeDescriptorContext context, object value, Attribute[] attributes)
        {
            PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(SelectionRange), attributes);
            return props.Sort(new string[] { "Start", "End" });
        }

        /// <summary>
        ///  Determines if this object supports properties.  By default, this
        ///  is false.
        /// </summary>
        public override bool GetPropertiesSupported(ITypeDescriptorContext context)
        {
            return true;
        }
    }
}

